Australia is one of seven countries responsible for more than half of global biodiversity loss, according to a study published today.

Key points:

Australia second behind Indonesia for biodiversity loss

Spending on conservation reduced loss

Habitat loss, invasive species drive species decline in Australia

Scientists based their findings on the worsening in conservation status of species between 1996 and 2008 on the International Union for the Conservation of Nature (IUCN) red list.

The IUCN red list uses a series of categories to rank how close a species is to extinction, from "least concern" through to "extinct in the wild".

Of the 109 countries studied, Papua New Guinea, Indonesia, Malaysia, India, China and the United States (primarily Hawaii) also ranked inside the top seven as the worst offenders on conservation.

The researchers conceded that species native to multiple countries presented an obstacle to their calculations, but lead author Anthony Waldron says they were able to narrow down where the pressures were coming from.

"Once you actually work out [which country] might have been responsible for the loss of diversity, Australia is standing there at number two," Dr Waldron said.

"I knew there were a lot of threatened species in Australia, but I didn't realise things were getting worse so quickly."

Compared to Australia, which recorded a biodiversity loss of between 5 and 10 per cent of the total global decline, the study published in Nature found Indonesia had "absolutely the highest number of declining species", representing around 21 per cent of the total decline during the period.

Reduction in biodiversity was calculated by looking at species that had their IUCN red list upgraded during the period, such as from "least concern" to "threatened", or "vulnerable" to "endangered".

The researchers believe that their data can be used to better target conservation efforts.

"What we've actually got is empirical proof that it's very easy to predict what is going to happen to your biodiversity based on this balance between the pressures and the money you put in to [limit the impact]," he said.

Environmental sustainability professor Barry Brook from the University of Tasmania said there were a number of pressures threatening biodiversity in Australia.

"The predominant one is landclearing — ongoing clearing for habitat. New South Wales and Queensland have been particularly bad for that over the past two decades," Professor Brook said.

"[But] it's also what's known as 'lags' or 'extinction debt'. That's where you've had this historical change over many decades and it takes time for extinction to catch up as populations are reduced and fragmented and lose genetic diversity, then gradually fade away."

He said that spending on conservation is worthwhile when it involves preserving habitat or targeting pests.

"Native biodiversity is definitely improved by removing invasive plants and to a lesser extent invasive species."

Outgoing threatened species commissioner Gregory Andrews caused a stir recently when he suggested there are bigger threats to Australian wildlife than habitat loss.

"If you look at where we've had the greatest rates of faunal decline, where Australia has had the highest levels of reductions in our animals has been on the Nullarbor Plain," Mr Andrews told the ABC earlier this month.

"On the Nullarbor Plain, I can tell you there is virtually no land clearing."

In her resignation from politics, Kelly O'Dwyer said she feared another miscarriage in Canberra, far from home. Her announcement is shocking for more than just party-political reasons, writes Emma A. Jane.